#include <reg52.h>
#define LED_all P2




void Delay(unsigned x)
{
	while (x)
	{
		x--;
	}
}

void main()
{
	int i = 0;
	while (1)
	{
		for (i = 0; i < 7; i++)
	    {
			LED_all = ~(0x01 << i);
	    }
	    Delay(20000);
	    for (i = 0; i < 7; i++)
	    {
			LED_all = ~(0x80 << i);
	    }
	
	}
	
}